1. Field of the Invention
The present invention relates generally to a dual trace display device, and more particularly to a dual trace display device in which two input signals are successively displayed on th same scanning axis of the display device changeably.
2. Description of the Prior Art
In a conventional dual trace display device, two input signals A and B are fed to input terminals 1 and 2 and then through pre-amplifiers 3 and 4 to a gate circuit 5, as shown in FIG. 1. The gate circuit 5 is supplied with a switching signal from a rectangular waveform generator 6 to pass therethrough the input signals alternately to an amplifier 7 and the output from the amplifier which is applied to the drive vertical axis of a cathode ray tube 11. A sweep signal generaor 9 is supplied through a switch 8 with the output from the pre-amplifier 4 or the amplifier 7 to produce a horizontal sweep signal in synchronism with the signal applied thereto. The horizontal sweep signal from the sweep signal generator 9 is applied through a amplifier 10 to drive the horizontal axis of the cathode ray tube 11. In this case, in synchronism with the switching of the two input signals, the level of the horizontal axis correspondng to the two input signals is switched to display the input signals A and B on a screen 11a of the cathode ray tube 11 in parallel with each other in vertical direction as shown in FIG. 4. Accordingly, the dual trace display device mentioned as above will be convenient for comparing the phase of the input signals A and B but is not preferred for comparing the amplitude of the input signals A and B.